Surface Plasmon Interferometer in Silicon-on-Insulator: Novel Concept for an Integrated Biosensor

We propose a novel configuration for a highly integrated and highly sensitive optical biosensor. The basic element of our sensor is a surface plasmon interferometer consisting of a thin layer of gold embedded in a silicon membrane. We investigate the performance of our sensor by simulation using eigenmode expansion. We calculate that refractive index changes in the order of 10-6 RIU (refractive index unit) are detectable for a component of length 10 mum. Moreover, we illustrate that the operation wavelength of our sensor can be tuned to a desired wavelength for a wide range of environmental refractive indices, making our device suitable for chemo- and biosensing